Pad for facilitating machining of castings.



A. E. HARRISON.

PAD FOR FACILITATING MACHINING 0F CASTINGS.

, APPLICATION-FILED no 30.1914.

Patented June 27, 1916.

E. HARRISON, F MILWAUKEE, WISCONSIN, ASSIGNOR TO ALLIS-CHALMERS TEANUFACTURING COMFANY, 0F MILWAUKEE, WISCONSIN, A CORPORATION OF DELAW'ARE.

PAD FOR FACILITATING MACHINING OF CASTINGS.

new and useful Improvement in Pads for Facilitating Machining of Castings, of which the following is a specification.

This invention relates to improvements in the construction of machine elements and particularly to means for facilitating machining .of cast machine elements or menihers.

An object of the invention is to provide means for facilitating machining of castings.

One of the more specific objects is to pro- I vide a plurality of local pads for a cast memher, the finlshing of which pads Wlll provide suitable joining surfaces of coaction with an adjacent member of a completed structure.

Another object is to provide a local pad which may be securely fixed into place within the cast member during the casting operation. L

A further object is to provide one or more pads with portions or projections which 1nterlock with adjacent portions of the cast member; and to secure the pad to the cast memberby fusion of metal.

Still another object is to provide a relatively soft and readily machinable cast-in pad which may? be finished without necessitating finishing of the relatively hard sur face of the main casting.

A clear conception of an embodiment of the invention may be had by referring to the drawing accompanying and forming a part of this specifica ion in which like reference characters designate the same or similar parts in the various views.

Figure 1 is a fragmentary sectional view of a pair of machine elements or members showing a. cast-in pad in one of the members,

the section being taken along the line I-I of Fig. Fig. 2 is a fragmentary end V t l? of one of the machine elements or members showingseveral of the local cast-in pads. Fig. 3 is an enlarged rear view of one of the pads removed from the casting. F 1g. 4 1s an enlarged end view of one ,of the pads removed from the casting.

In machining large castings for certain purposes, such as in' crushers, revolv ng Qscrens and, like machines, it has been found Specification of Letters Patent.

preferably made of cast iron.

Patented J1me 1m 6.

Application filed November 30, 1914. Serial No. 875,189.

unnecessary to provide a close fit between the entire adjacent surfaces of the assem' bled structure. It has also been found undesirable to remove only the surface scale of large castings in order to finish the same. :lhe present invention contemplates the elimination of the necessity of finishing the entire surfaces of the castings and also the ellmination of the danger of damaging the machine tools during the finishing operat1on. While the invention is shown as applied to a body of revolution it should be understood that it is also applicable to bodies having rectilineal elements and to other forms of bodies.

Referring specifically to Figs. 1 and the machine element or member 2 is constructed of cast metal and is provided at its periphcry with a series of local soft metal pads l The pads 1 when finished or machined, have curved surfaces 7 and plane surfaces 6 which are adapted to coact with the finished adjacent in- 'ternal and end surfaces of the member 3 respectively. The members 2, 3, may be any machine elements between which there should be a reasonably close fit when the parts are assembled.

The individual pads, views of one of which are shown in Figs. 3 and 4, have body portions of angular formation and are each provided with. a pair of dovetailed projections & which are separated by means of a dovetailed recess 8. The projections l are united with the adjacent portion of the main body portion bymeans of cylindrical neck portions 5.

The pads 1 are formed preferably of soft iron either by casting or any other process,

so that they may be readily machined without danger of injury to the machine tools. WVhen it is desired to apply the pads l to a cast member, the pads l are first properly arranged in the mold in the usual manner, after which the metal is cast about them as shown in Figs. 1 and The cast metal enters the spaces between the projections 4 and the main body of the pad, surrounding the neck portions 5, and also filling the recess 8, thereby forming positive interlocking p0r-. tions on the pad and member for holding the two elements together. During the cast ing, the metal-of the-pads l will become sufficiently heated to produce welding of the pads to the cast member. It has been found,.

howent'r that the welding of the parts alone is not sutficient to produce a joint Which is firm enough to prevent displacement of the pads during machining. With the use of dovetailed and interlocking projections on the pads and member, a firm connection which is capable of withstanding strains due to machining is formed. After the pads l have been cast into the member 2, thesurfaces 6, 7, of the pads may be readily machined to the proper dimensions.

It should be understood that it is not de-" sired to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

It is claimed and desired to be secured by Letters Patent,-

1. As an article of manufacture, a pad having a machin'able face and having opposite end faces each at an angle to said machinable face and serva-ble as abutments in a casting during machining of said machinable face, and a projection extending transversely of said end faces and interlocking with said casting.

2. As an article of manufacture, a pad having a machinable face and having opposite end faces each at an angle to said machinable face and servable as abutments in a casting during machining of said machinable face, and a projection extending transversely of said endfaces and interpossible between said As an article of manufacture, .at pad 7 comprising a body portion havingkjgwmachinable face and having opposite end faces each at an angle to said machinable face and servable as abutments in a'ca sting during machining of said machinable face, a projection extending transversely of said end faces and interlocking with said casting, and aneck portion connecting said body portion and said projection.

4. As an article of manufacture, a pad having an L-shaped cross-section, a dovetailed projection extending from one leg of the L, said projection being spaced from and substantially parallel to the other leg of the L, and a neck portion connecting said projection with the last mentioned leg of said L.

In testimony whereof, the signature of the inventor is aflixed hereto in the presence of two Witnesses.

ALBERT E. 'HARRTSOX. Witnesses:

. V. H.-LIEBER,

G. F. DEVEIN. 

